With big and fast global selling of 3C-information products and high-end home appliances, metal casing has already become the basic part of many products.
In general, in addition to the characteristics of high strength and noble quality, metal casing offers better heat dissipation, preventing the shortening of the lifespan of electronic components due to a high temperature.
However, due to structural constraints, some device casings cannot be directly made out of a metal sheet material. FIG. 1 illustrates the fabrication of a metal keyboard cover according to the prior art. As illustrated, a stamp forming technique and a plastic injection molding technique are employed to form a plurality of through holes 121 in a metal sheet material 12 and to make a plurality of mating stub tubes 14 respectively, and then the mating stub tubes 14 are respectively bonded to the top wall of the metal sheet material 12 around each through hole 121, and thus a keyboard cover 16 is obtained.
The keyboard cover 16 thus made comprises a planar body part 161, a plurality of key-switch holes 163 cut through the planar body part 161, and a flange 165 located at the planar body part 161 around each key-switch hole 163.
The aforesaid keyboard cover 16 is made by bonding separately made components together. In addition to the problem of discontinuous material at the junction, the bonding quality also determines the durability of the product. Further, under the effects of climate and temperature changes, the components of the keyboard cover may drop off easily.